Journey on a Path Less Traveled

One of the next requirements on my list was to find an ideal solution for mobile (portable) air provision. Although portable air can be used in a number of different scenarios, there are two primary uses in an expeditionary-type vehicle, running pneumatic air tools and refilling the vehicle’s tires.

Off-roading adventures tend to be a bit more demanding on a vehicle and as such, the potential for damage is much more likely. In the event that vehicle trail repairs are required, a portable air solution can be used to power a number of specialized air tools such as an impact wrench or grinder. This can make a huge difference in the amount time and effort required to get a vehicle back on the trail in serviceable condition. Using air tools on the trail does have its drawbacks, however. It all depends on the individual tool, but some of them tend to be quite greedy when it comes to air flow. Be sure and check the cubic feet per minute (CFM) rating of any tool prior to purchasing to ensure it’s compatible with your portable air solution’s maximum supply of pressure and flow.

A secondary, and perhaps more popular, use for portable air solutions is refilling a vehicle’s tires. For many off-road adventures, it is not uncommon for the vehicle’s tires to be intentionally aired down once the terrain becomes more challenging. Please note that for safety reasons, you should always maintain full tire pressure (based on the tire manufacturer’s specifications) when traveling at speeds higher than 10mph. Even with beadlocked wheels, traveling with low tire pressure at high speeds is a recipe for disaster. At low speeds, however, the advantages to airing down are many.

In slow-speed, controlled maneuvers, airing down can be highly advantageous. Reducing the vehicle’s tire pressure will generally increase traction because the footprint of the tire is dimensionally increased. More “rubber to the road” means a greater surface area for gaining grip. Most off-road adventures are conducted at very low speeds and the increased traction gives drivers better control over the vehicle. Better control will obviously reduce the chance of damage to vehicle components and increases the odds of making it past an obstacle successfully. But what happens when the expedition heads back to the pavement? This is where portable air solutions are ideal.

Like so many other off-roading debates, there are generally two sides to the portable air debate. One side prefers an on-board compressor with an optional storage tank for compressed air. The other side forgoes the compressor altogether and opts for a tank solution using compressed carbon dioxide (CO2). The ideal option would be a combination of on-board compressor and CO2, but this can also rack up the configuration cost considerably. So most tend to stick with either one solution or the other. Based on the reviews and feedback from actual owners, I opted for a CO2 solution. One of the primary reasons I elected to go with a CO2 solution was based on performance.

In an independent review, only one compressor solution ranked higher than CO2 tanks in terms of time required to refill a tire. On average, a CO2 tank will deliver higher pounds per square inch (PSI), with a considerably higher CFM rating than that of an on-board compressor. This increased performance does not come without cost however, as most CO2 solutions are priced higher than their compressor counterparts. So there is a trade-off, but for my needs I preferred to pay a little more up front, knowing that I could air up quicker and run higher-end tools down the road.

After conducting my usually research, I decided to go with a CO2 solution from Powertank. They have a long-standing reputation for quality and performance in the off-roading community and have been in the business for over a decade. That’s not to say there aren’t other less expensive solutions available. CO2 solutions can be had from Ultimate Air or The Source, both of whom have a great reputation as well. I opted for a Powertank solution based on the variety of tank configurations (colors and sizes) as well as their custom high-flow regulators. Powertank puts together some really nice CO2 packages or you can even do a custom order for specific parts if you prefer.

In the case of the FJ Cruiser, there is an ideal mounting location on the driver’s side of the rear cargo area. The recessed area above the rear wheel well has the perfect dimensions for a 10lb Powertank solution. But mounting the tank itself becomes a bit more challenging when you consider the weight and size of a CO2 tank. The ten pound rating is based on the tank’s capacity for holding CO2, not the tank itself. A 10lb Powertank, including CO2, regulator, guard, boot and mounting bracket weighs in just over 30lbs. That may not seem like much weight but in the event of a collision or roll-over, a 30lb projectile can cause some serious damage. So I needed to ensure the mounting location was secure. Luckily, I had just finished installing a Springtail Solutions Heavy Duty side rack in anticipation of just this type of scenario.

UPDATE:

I’ve used the Powertank 10lb setup now on virtually every trail run I’ve made and it’s worked beautifully every time. I am capable of airing up all four tires from ~12lbs of pressure to ~33lbs in a matter of minutes. The time saved is a nice bonus since the last thing I want to worry about is spending 30 minutes waiting for a compressor to slowly fill each tire after a long day on the trail. The CO2 tanks have yet another distinct advantage over a compressor scenario because they have fewer parts to wear out. Besides the regulator, there are very few complex mechanical parts to a tank setup. The same can not be said for a compressor setup, potentially suffering from overheating or other issues related to physical wear and tear. A CO2 solution is also much quieter than a compressor, lacking the typical noisy chatter of a small on-board motor. So for me, the CO2 solution is the hands-down winner. But there are a few minor issues I’d like to point out to potential buyers looking for a CO2 solution.

Advertising is designed to sell a product. Period. I don’t want to point fingers at any particular vendor, but buyers should keep in mind that any quotes given for “tires filled per tank” are highly subjective. I was greatly mislead by initial reports that a single 10lb tank of CO2 was capable of refilling 80 tires. A gross over-estimate, but being new to the CO2 world, I bought into it hook, line and sinker. The total number of refills from a single tank is greatly dependent on the capacity of the tank, as well as how much pressure is being added to each tire. Some folks only drop their pressure 5-10lbs per tire, where others may lose up to 25 or 30lbs. It depends entirely on your pressure preference as well as the type of tire you happen to run.

Some of the other minor issues are related to refills. For those new to CO2, you can’t just take your tank down to your local Home Depot and expect them to exchange it for a full one. Firstly, big box stores like Home Depot and Lowes don’t do CO2. Secondly, if you pay for a custom tank setup like a Powertank, you certainly don’t want to trade in your nicely-finished, powder-coated tank for a 4-year-old dinged up aluminum shell of a model. So you’ll need to make sure there’s someone nearby that can refill CO2 tanks. If you’re unsure as to where to look, try a local welding supply store. If they don’t have the ability, they can probably recommend someone nearby who does.

A 10lb fill of CO2 will usually run somewhere between $10-$20 depending on the supplier. Most shops will default to the weight rating that is stamped on the side of the tank. So if you’re dropping off a tank with a guard, regulator, or other accessories, make sure the shop knows the proper empty weight before filling. I made this mistake my first few trail runs and was only getting about 7lbs of CO2 even though I was paying for 10lbs.

Tanks designed to hold compressed gas, like those used with CO2 scenarios, are regulated and must meet a minimum set of criteria to qualify for refills. These types of tanks must undergo a certification every five years to ensure they are safe for use. I bought my tank new so I’ve got a ways to go before I can report on this particular aspect. But for anyone buying used tanks or piecing together their own setup, this is definitely something you want to keep in mind. If a tank fails certification, it means it won’t hold pressure properly. Re-certifications are put into place as a safety measure to help reduce injuries due to faulty tanks. CO2 suppliers make note of the certification date prior to refills so if your tank is outside the certification date, they won’t fill it. As far as I know, there is no way to repair a tank, so if a tank fails certification, you’d be looking at buying another new or used tank to replace it.

Companies like Powertank, Ultimate Air and The Source put together some very nice packages that make it quick and easy to get up and running with CO2. If you have the money and don’t wish to hassle with piecing together a system on your own, I highly recommend taking this route. I have, however, seen a lot of folks piece their own custom systems together using off-the-shelf parts. They usually save more money doing this but it requires a more detailed knowledge of CO2 systems and the inherent dangers of dealing with any compressed gas.

One of the main advantages of a do-it-yourself type of setup is that you can simply exchange the tanks each time, which means no waiting 2-3 days between drop-off and pick-up. CO2 suppliers will typically do their fills on certain days or once they receive a certain number of tanks. This is because they have to flush the entire system once they’re done filling which means they end up bleeding 10-20lbs of CO2 into thin air. So they generally wait until they get enough tanks to make charging the system worth their while.

At some point, I may dive in and add an on-board compressor to my setup. I do carry a small portable compressor in the event that I run out of CO2 unexpectedly. But as of late, I’ve given more serious consideration to purchasing a second, larger CO2 tank instead. Given the obvious advantages (at least to me), a spare tank would mean another 20lbs of CO2, giving me the ability to run tools and refill tires that much longer. My only difficulty with a 20lb tank is how to secure it. As of right now, I have no way to safely lock down something that size so I’ll need to do some more research before heading down that road.

About Expeditionr

Expeditionr is a one of several blogs owned and maintained by Jeff Todnem. As an off-road enthusiast, Jeff spends a good portion of his time “in the field” but also enjoys writing and sharing his experiences in hopes that it might help others. His current platform of choice is Toyota’s FJ Cruiser, a vehicle designed specifically with rugged outdoor conditions in mind. Since he purchased the FJ in January of 2007, he’s spent a great deal of time performing various upgrades and modifications. This site serves up a number of articles detailing these modifications, as well as the post-installation results. Jeff also enjoys writing about planning, preparation and some of the gear required for longer-term off-roading expeditions. If you enjoy this site and the content it provides, please feel free to post comments or contact Jeff directly through his contact page.

2 Responses

Thanks for the questions. The manufacturer I selected for mobile air supply was Powertank, and yes, they are still very much in business. Due to its overwhelming popularity, you can actually find the same package I purchased back in 2009 (with pricing), by visiting the following url: http://powertank.com/products/sfID1/13/productID/440

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